Lamp assembly means



1933. H. A. DOUGLAS LAMP ASSEMBLING' MEANS Filed Jan. 30, 1931 2 Sheets-Sheet l H. A. DOUGLAS LAMP ASSEMBLING MEANS Oct. 24, 1933.

Filed Jan. 30, 1931 2 Sheets-Sheet ,Z'ar/yy J7. Jazzy Patented Oct. 24, 1933 UNITED STATES PATENT OFF E 1,932,265 I LAMP ASSEMBLY MEANS Harry A. Douglas, Bronson, Mich.

Application January 30, 1931. Serial No. 512,373

' 4 Claims. (01.240-141) I My invention relates to assembly means for incandescent electric lamps and their mountings and is of particular service where such mountings are in the form of concave reflectors for automobile headlights and the lamps are assembled therewith by means inclusive of sockets. The reflector may be parabolic having an opening therethrough through which'the socket projects. This opening is advantageously at the crown of the reflector and is margined by portions of the reflector that are equidistant from the axis of the reflector and engage the socket to permit the socket axis to be positioned upon the axis of the reflector. My invention includes the provisionof spring means which presses the socket against the mounting at bearing points distributed aroundthe axis of the socket. The bearing points on the socket determine a plane perpendicular to the axis of the socket, and the spring, which surrounds the socket,. presses the socket axially from pressure points distributed around the socketaxis, said pressure'points being in a plane perpendicular to the socket axis, thus positioning the socket axially with respect to the reflector and maintaining the, socket axis normal with respect to-the reflector and consequently upon the axis ofthe reflector. This spring may be in the form of a leaf spring keyed to the socket and transmits pressure tothe socket by pressing against the rear surface of the reflector at pressure points'radiallyaligned with the bearing points of the socket, but farther from the axis of the socket. In one aspect the invention is also inclusive of interlocking means between thesocketv and the reflector, so that the socket can be assembled with the reflector in only one way and the socket is positioned rotatively with respect to the reflector. The socket has bayonet channels to receive bayonet pins upon the lamp base. The lighting center of the lamp filament is upon the socket axis when the parts are properly assembled and the spacing between this lighting center and the bayonet. pins plus the spacing between the place where the bayonet pins engage the socket and the reflector,

and its focus, whereby said lighting center and the reflector focus are brought into coincidence. The invention may be understood by reference to the illustrative construction shown in the accompanying drawings in whichv Figure l is a view showing an incandescent lamp and circuit contact terminals'in elevation and associated parts insection, of the illustrated .55 embodiment'ofthe invention; 1

a ,11 is inserted in the slot 12, which is shown closed are equal to the spacing between the reflector ,5

Figure 2 is a side elevation of the socket and a portion of the lamp base, showing associated parts in section;f H A Figure 3 is a section taken on the line 33 of Figure l;

Figure 4 is a sectional view online i-4 of Figure 1;

Figure 5 is a sectional View of a complete automobile headlight embodying the illustrative construction of my invention;

Figure 6 is a sectional viewon line 66 of Figure 1; and i Figure '7 is a perspective view illustrating some of the parts in separated relation. a

The headlight here shown for illustration is inclusive of a parabolic reflector 1 whose reflecting face is covered by alight transmitting closure 2 which may be of glass. This closure is held against the front of .the reflector by an assembling ring 3 which also serves to assemble the reflector with a concave back 4. The construction of the peripheral rim portion of the reflector with the back and the construction of the parts 3 and 4 may be of any well known or suitable characterand form'no novel parts in my pres ent invention on which account further descrip: tion of these parts need not be given. The embodiment of the invention shown in this instance isinclusive of an incandescent lamp having a generally cylindrical lamp base 5 which is laterally enlarged as by means of bayonet pins 7 6.- The generallycylindrical socket 7, which snugly receives the base 5, is provided with bayonet channels 8 having seats 9,..w-hich .-receive the aforesaid bayonet pins. 90

The reflector '1 has an opening therethrough, essentially circular and substantially the diameter of the socket '7, the arcuate margins 10 of which opening are equidistant from the principal axis of the reflector. The portion of the reflector margining the opening is inwardly extended as at 11 and the socket 7 has a slot -12 permitting the passage of the extension 11. When the socket is to be assembled with the reflector, the extension 00 at bothends, by canting the socket with respect passage of the lugs 15 which are formed on the socket 7 by being struck outwardly from the body thereon. By spacing the slot 12 and the enlargements 14 unequally about the axis of the opening 10 the extension 11 and lugs 15 may be equally spaced. The lugs 15 as shown are struck directly outwardly from the socket material so that the lugs are connected to the socket at each end of each lug transversely of the socket and are disconnected longitudinally of the socket. -Thus the bearing surfaces provided by the lugs 15 are in a single plane. When the extension 11 has been seated in the seat 13, the lugs 15 bear against the reflecting surface of the reflector and, together with the seat 13 provide three bearing points for the socket on the reflector distributed around the axis of the socket. As here shown these bearing points are substantially 120 degrees apart. These bearing points 13, 15, 15 determine a plane perpendicular to the axis of the socket 7. If desired the crown of the reflector may be flattened in a plane perpendicular to the principal axis as clearly shown in Figures 1, 4 and 5 of the drawings.

A leaf spring 16 has an opening formed through its base of the diameter of the socket. The portion of the spring margining the said opening is inwardly extended as at 17 to; engage corresponding recesses 17a at the rear end of the socket '7, thus keying the spring to the socket. The spring 16 is retained in assembly with the socket by means inclusive of a contact carrier comprising an insulating disc 18 of the diameter of the bore of the socket '7 and having the shoulder portions 19 which are adapted to lie in recesses in the socket between the prongs 20 which extend longitudinally beyond the rear end of the socket. The prongs 20 are adapted to be turned down. to lap the disc 18 to secure the disc and the spring 16 in place, in a plane perpendicular to the socket axis.

"The spring 16 has three legs which are radially aligned with but extend radially farther from the socket axis than the bearing points 13, 15, 15 (as best shown in Fig. 3). These spring legs normally engage the rear surface of the reflector at pressurepoints defining a relatively large triangle perpendicular to the axis of the socket. When the bearing points 13, 15, 15 are in engagement with the reflecting surface of the reflector, the spring 16 is tensioned between the reflector and the socket and presses rearwardly upon the socket from pressure points distributed around the socket axis to press the bearing points 13, 15, 15 against the reflecting surface of the refiector. Since the pressure'points of the spring are aligned with the bearing points of the socket and are relatively far from the socket axis, the axis of the socket is positively maintained coincident with the axis of the reflector and variations from that coincidence are guarded against by the relatively long level arm effect of the spring 16.

The spacing between the lighting center of the lamp filament 21 and the bayonet pins'6 plus the spacing from the seats 9 to the reflector 1 being equal to'the spacing between the reflector and.

the reflector focus, it follows that said lighting center of the lamp filament and the focus of the reflector are brought into coincidence when the bayonet'pins 6 are seated in the seats 9, aswill hereinafter morefully appear. 7

The lamp illustrated is a double pole lamp whose filament 21 is the bright light producing filament of the lamp, one terminal of which is connected with one of the lamp contacts 22 upon from the invention. 7

the rear of the lamp base. A filament 21a, which is the dim light producing filament of the lamp is included between the other of the lamp contacts 22 and a metallic sheath which constitutes a part of the lamp base and to which the filament 21 is also connected. By suitable switching mechanism, not illustrated, either the filaments 21 or 21a may be included in circuit or both may be excluded from circuit. Each cir-' slides within a metallic sleeve 25 carried by the insulating disc l8. Since the lamp base is inserted in the socket against the pressure of the springs 24, the springs 24 press the bayonet pins 6 into engagement with the seats 9 of the bayonet channels 8. A slot 27 in the outer end of the socket 7 permits the socket to be slightly contracted at its lamp receiving end, thereby enhancing the intimacy of the socket and the lamp base and further guarding against variations from coincidence of the lighting center of the lamp filament and the reflector focus. constructed and arranged the lamp filament is maintained in a single predetermined fixed position with respect to the reflector. words, the socket can occupy but one predetermined fixed position rotatively and axially with respect to thereflector and the lamp filament can occupy but one predetermined fixed position rotatively and axially of the socket. Thus not only is the filament 21 maintained coincident with the reflector focus but the filament 21a is maintained in a fixed position with respect to that focus. The filament 21a is desirably spaced slightly above therefiector focus to constitute the intermediate driving light of the automobile. As shown in the drawings, slot 27 is narrower than the inwardly extended portion 11 of the reflector transversely of the socket, so that this lar to the spring 15, and adapted to receive the i wires 23a and a plug 28 of well known construction.

Subject matter disclosed and not claimed in this application is claimed in my copending case,

Serial No. 5l2,375', filed January 30, 1931.

Such changes may be made as fall within the scope of the following claims without departing Having described my invention-"i claim:

1. The combination with a reflector having a generally circular opening therethrough .the'margm of said opening having aportion extended inwardly into the opening and having two laterally extended enlargements, said portion and said enlargements being unequally spaced apart about of the reflector, said=slot being closed at both ends whereby the socket is inserted in the opening As so ion iio

only by a canting movement; lugs on the socket passing through the enlargements of the reflector I opening; a bayonet seat insaid slot receiving the inwardly extended portion of the reflector, said bayonet seat and said lugs being equally spaced about the axis of the socket and said bayonet seat and said lugs having surfaces engaging the reflector in a plane perpendicular to the socket axis when said portion is in its seat; and a three-legged spring carried by the socket and engaging the reflector to press the socket longitudinally and maintain the said portion in its seat and said lugs in engagement with the reflector.

2. The combination with a reflector having a generally circular opening therethrough, the margin of said opening having a portion extended inwardly into the opening and having two laterally extending enlargements; of a cylindrical socket in said opening; a longitudinal slot in the socket receiving the inwardly extended portion of the reflector; lugs on the socket passing through the enlargements of the reflector opening; a bayonet seat in the said slot receiving the said inwardly extended portion; a three-legged springcarried by the socket and engaging the reflector to press the socket longitudinally and maintain the said portion in its seat and said lugs in engagement with the reflector, one of the legs of the spring being radially aligned with the said bayonet seat and the other two legs being radially aligned with each of the said lugs, and permanent interengaging means between the spring and socket maintaining the legs of the spring in said radial alignment. z

3. The combination with a reflector having a circular opening therethrough, said reflector having a portion extended inwardly into the opening; of a cylindrical socket in said opening of substantially the diameter thereof; a closed longitudinal slot in the socket receiving the inwardly extended portion of the reflector by a canting movement only; a bayonet seat in the slot for the said portion; lugs on the socket engageable with the reflector; and a spring carried by the socket and tensioned against the reflector to press the socket longitudinally and maintain the said portion in its seat and said lugs in engagement with the reflector.

4. In a fixed focus lamp assembly.means, the combination with a parabolic reflector having a generally circular opening therethrough substantially concentric with its principal axis; of a cylindrical socket in said opening; interengaging means on the socket and reflector including projections on both socket and reflector providing a three-point support for the socket on the reflector, said interengaging means being equally spaced about the socket axis and defining a plane perpendicular to the socket axis whereby the socket axis is fixedly positioned coincident with the axis of the reflector opening and the socket is supported in but one rotative position with respect to the reflector; and a three-legged spring permanently keyed to the socket with its legs radially aligned with the interengaging means and tensioned against the reflectorto press the interengaging means together.

HARRY A. DOUGLAS. 

